Electrical overstress (EOS) is a challenge for legacy input-output (I/O) buffers that are required to operate either on a high power supply (e.g., 3.3V) for backward compatibility or on a low power supply (e.g., 1V) for next generation low power applications. For example, Universal Serial Bus (USB) 2.0 compliant I/O buffer is required to offer functionality in classical (CL) mode in which signals are driven by the buffer using 3.3V power supply, and also required to offer functionality in high speed (HS) mode in which signals are driven by the buffer using 1.0V power supply. For the buffer to provide functionality for both modes of operation, dual buffer designs are used which increase area and power.